what sort of gain is calculated for the twin lead J poll design?
Regards
Colin
----- Original Message -----
From: "John Miller" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, February 15, 2005 4:44 PM
Subject: Re: Twin lead J pole


> Well, plans were sent to the list a couple weeks ago but I can send them
> again no problem.
> JPole Antenna
>       A JPole Antenna
>       In emergencies, you are likely to have to put up an antenna
somewhere.
> The
>       JPole described here is cheap, easily made, and works very well.
Plus,
>       it's portable!
>       Home Are you ready to use your amateur radio communications skills
in
> a
>       real emergency?
>       This page, taken from various Internet sites, will help, by enabling
> you
>       to build your own roll-up Jpole antenna.
>       The 2-Meter 300 Ohm TV Twin-lead Roll-up J-pole.
>       As we all know, the antenna is the most important part of any
> transmitter
>       system. It must be placed as high as possible, properly matched to
the
>       transmitter, and designed to effectively radiate the power applied
to
> it.
>       The antenna that we are going to construct will be made from
ordinary
>       300-Ohm TV Twin lead wire. This wire is available at almost every
>       hardware, drug store, and other stores that carry such items as
> telephone
>       extension cords.
>       In the diagram below you will see the construction details of the
> antenna.
>
>       Now, on to the step by step.
>       Tools: Ruler, Wire strippers, Wire Cutters, Soldering Iron.
>         Measure 54" of Twin lead and mark this spot with some masking
tape.
> Cut
>         the wire about 1 ½ inches longer than this measurement. If this is
> your
>         first attempt at building something, you may want to leave 4 " of
> extra
>         wire on the piece you are working with. This will allow an
> additional
>         attempt of the critical portion of construction.
>
>         Remove the center insulation from the bottom 1-inch of twin lead.
> Strip
>         the insulation off of the bottom section of twin lead (only the 1
> ").
>         Connect the wire together at this point and solder.
>
>         From the splice you just made at the bottom, measure up about 1 "
> and
>         remove ½ " - ¾ " of insulation from each conductor. This is where
we
>         will be attaching the coax.
>
>         From the splice measure up one side 16 ½" . CHECK THE MEASUREMENT
> TWICE.
>         Cut a gap on this side about ¼" wide. Be sure to remove the
> conductive
>         material from the notch.
>
>         From the splice, re-measure the total length to 54 " and trim the
> top.
>
>         Attach some coax to the opened area of the wire about 1 ¼" from
the
>         splice. The shield of the coax MUST connect to the notched side.
>
>         Attach a suitable connector on the end of the coax for your
> transmitter
>         and GO!
>
>
>       Note: The antenna can be hung from almost anything using some string
>       through a hole in the insulation about 1" from the top.
>
>
> © Michael Willems 1999
> Comments: [log in to unmask]
>
> ----- Original Message -----
> From: "Colin McDonald" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Tuesday, February 15, 2005 4:39 PM
> Subject: Re: Twin lead J pole
>
>
> > John:
> > send us a discription of the antenna and how you built it.
> > Regards
> > Colin
>